Messages in this thread |  | | | Date | Tue, 23 Mar 2004 14:44:27 +0530 | | From | Dipankar Sarma <> | | Subject | Re: CONFIG_PREEMPT and server workloads |
| |
On Fri, Mar 19, 2004 at 11:30:16AM +0100, Takashi Iwai wrote: > > The unavoidable worst case is in the RCU callbacks for dcache shrinkage - > > I've seen 25 millisecond holdoffs on the above machine during filesystem > > stresstests when RCU is freeing a huge number of dentries in softirq > > context. > > hmm, this wasn't also evaluated in my tests. > it's worthy to try. thanks for the info.
Please do. This would be a very interesting data point.
> > > This if Hard To Fix. Dipankar spent quite some time looking into it and > > had patches, but I lost track of where they're at. > > couldn't this tasklet be replaced with workqueue or such?
Close. I am using per-cpu kernel threads to hand over the rcu callbacks if there are too many of them. It depends on CONFIG_PREEMPT on better latency from there onwards.
I can use a workqueue, but I needed the flexibility experiment with the kernel thread for now.
Thanks Dipankar - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |